In critical care and home care health service centers including hospitals, clinics, assisted living centers and the like, care giver-patient interaction time is at a premium. Care givers are needed to respond rapidly to significant health conditions because any delay can represent the difference between life and death. Systems of centralized monitoring have been developed to more efficiently utilized care givers' time, by transmitting physiological data from each patient (or from graphically-dispersed critical care health service centers) to a centralized location.
At this centralized location, a single or small number of technicians monitor all of this patient information to determine patient status. Information indicating a patient alarm condition will cause the technicians and/or system to communicate with care givers to provide immediate patient attention, for example via wireless pagers and/or cell phones, and/or by making a facility-wide audio page.
The information transmitted to the centralized location could be performed over a local area network, such as with “WiFi” network based on IEEE 802.11 standards. The problem, however, with this network is that it is often difficult to secure sufficient local area network access for the purpose of providing centralized monitoring. Moreover, when a patient is located remotely from a critical care health service center (e.g., at home), access to traditional local area network facilities such as a WiFi network may be unavailable or not sufficiently reliable to support critical care monitoring applications.
An alternative to WiFi is ZIGBEE, which is based on the IEEE 802.15.4 standard for wireless personal area networks. ZIGBEE networks have previously been used for collecting information from a variety of medical devices in accordance with IEEE 11073 Device Specializations for point-of-care medical device communication, including for example pulse oximeters, blood pressure monitors, pulse monitors, weight scales and glucose meters.
The advantages of ZIGBEE networks are that the network is dynamically configurable (e.g., “self-healing” mesh configurations) and operates with low power requirements (e.g., enabling ZIGBEE transceivers to be integrally coupled to the medical devices under battery power). However, transmission ranges between individual ZIGBEE transceivers are generally limited to no more than several hundred feet. As a consequence, ZIGBEE networks are generally unusable for centralized monitoring locations located off-site.
The networks are not the only issue. In some cases the physiological data from each patient may relate to significant health conditions. However, sometimes the data may not be communicated fast enough to the local care givers because of delay and/or signal interference. Further, even if communicated to the care givers, they may not react quickly or still require outside assistance, such as emergency 911 responders.